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use std::io::Error;
use super::rel::*;
use super::exec::*;
#[derive(Debug)]
pub enum DataFrameError {
IoError(Error),
ExecError(ExecutionError),
InvalidColumn(String),
NotImplemented
}
impl From<ExecutionError> for DataFrameError {
fn from(e: ExecutionError) -> Self {
DataFrameError::ExecError(e)
}
}
impl From<Error> for DataFrameError {
fn from(e: Error) -> Self {
DataFrameError::IoError(e)
}
}
pub trait DataFrame {
fn repartition(&self, n: u32) -> Result<Box<DataFrame>,DataFrameError>;
fn select(&self, expr: Vec<Expr>) -> Result<Box<DataFrame>,DataFrameError>;
fn filter(&self, expr: Expr) -> Result<Box<DataFrame>,DataFrameError>;
fn sort(&self, expr: Vec<Expr>) -> Result<Box<DataFrame>,DataFrameError>;
fn write(&self, filename: &str) -> Result<(),DataFrameError>;
fn col(&self, column_name: &str) -> Result<Expr,DataFrameError>;
fn schema(&self) -> Schema;
}